Biomarcadores de enfermedad de Alzheimer en deterioro cognitivo leve: experiencia en una clínica de memoria de Latinoamérica / Biomarkers of Alzheimer's disease in mild cognitive impairment: Experience in a memory clinic from Latin America

Objetivo: El objetivo de este estudio fue investigar el rol y pronóstico de los biomarcadores de enfermedad de Alzheimer en pacientes con diagnóstico clínico de deterioro cognitivo leve (DCL) en una clínica de memoria de Latinoamérica.MétodoOchenta y nueve pacientes con DCL, 43 con demencia tipo Alzheimer y 18 controles normales apareados por edad, sexo y escolaridad fueron estudiados con un extenso protocolo demográfico, neurológico y neuropsicológico en la clínica de memoria del Instituto FLENI de Buenos Aires. Todos completaron una RM cerebral, una PET con FDG, una PET con estudios amiloideo (PIB), genotipificación de APOE y estudio de Aβ1-42, tau and f-tau de líquido cefalorraquídeo. Basado en la presencia/ausencia de patología amiloidea y neurodegeneración los pacientes fueron categorizados como A+/A− y N+/N− respectivamente.ResultadosEn el estudio de líquido cefalorraquídeo el 18% de los controles, el 64% de los DCL y el 92% de las demencia tipo Alzheimer tenían patología amiloidea; y un 11% de los controles, el 6% de los DCL y el 8% de las DTA eran sospechosos de fisiopatología no Alzheimer. En el seguimiento a los 30 meses el 45% de los DCL con amiloide positivo y el 20% de los que presentaron amiloide negativo progresaron a demencia.ConclusionesEste estudio muestra el pronóstico de los DCL basado en los biomarcadores, y respalda su importancia en la toma de decisiones en la práctica diaria. (AU)

Objective: This study aimed to investigate the role and prognosis of Alzheimer disease biomarkers in patients with mild cognitive impairment (MCI) at a memory clinic in Latin America.MethodsWe studied 89 patients with MCI, 43 with Alzheimer-type dementia, and 18 healthy controls (matched for age, sex, and educational level) at our memory clinic (Instituto FLENI) in Buenos Aires, Argentina. Patients and controls underwent an extensive demographic, neurological, and neuropsychological assessment. All subjects underwent a brain MRI scan; FDG-PET scan; amyloid PET scan; apolipoprotein E genotyping; and cerebrospinal fluid concentrations of Aβ1-42, tau, and phosphorylated tau. Patients were categorised as positive or negative for the presence of amyloid pathology and neurodegeneration.ResultsAmyloid pathology was observed in cerebrospinal fluid results in 18% of controls, 64% of patients with MCI, and 92% of patients with Alzheimer-type dementia. Suspected non–Alzheimer disease pathophysiology was found in 11% of controls, 6% of patients with MCI, and 8% of patients with Alzheimer-type dementia. At 30 months of follow-up, 45% of amyloid-positive patients with MCI and 20% of amyloid-negative patients with MCI showed progression to dementia.ConclusionsThis study demonstrates biomarker-based MCI prognosis and supports its role in clinical decision-making in daily practice. (AU)

Biomarkers of Alzheimer's disease in mild cognitive impairment: Experience in a memory clinic from Latin America. / Biomarcadores de enfermedad de Alzheimer en deterioro cognitivo leve: experiencia en una clínica de memoria de Latinoamérica.

OBJECTIVE: This study aimed to investigate the role and prognosis of Alzheimer disease biomarkers in patients with mild cognitive impairment (MCI) at a memory clinic in Latin America. METHODS: We studied 89 patients with MCI, 43 with Alzheimer-type dementia, and 18 healthy controls (matched for age, sex, and educational level) at our memory clinic (Instituto FLENI) in Buenos Aires, Argentina. Patients and controls underwent an extensive demographic, neurological, and neuropsychological assessment. All subjects underwent a brain MRI scan; FDG-PET scan; amyloid PET scan; apolipoprotein E genotyping; and cerebrospinal fluid concentrations of Aß1-42, tau, and phosphorylated tau. Patients were categorised as positive or negative for the presence of amyloid pathology and neurodegeneration. RESULTS: Amyloid pathology was observed in cerebrospinal fluid results in 18% of controls, 64% of patients with MCI, and 92% of patients with Alzheimer-type dementia. Suspected non-Alzheimer disease pathophysiology was found in 11% of controls, 6% of patients with MCI, and 8% of patients with Alzheimer-type dementia. At 30 months of follow-up, 45% of amyloid-positive patients with MCI and 20% of amyloid-negative patients with MCI showed progression to dementia. CONCLUSIONS: This study demonstrates biomarker-based MCI prognosis and supports its role in clinical decision-making in daily practice.

Utility of the Spanish version of the Everyday Cognition scale in the diagnosis of mild cognitive impairment and mild dementia in an older cohort from the Argentina-ADNI.

INTRODUCTION: The performance of activities of daily living in elderly patients with memory disorders is directly related to living independently and to autonomy. Documenting and assessing functional capacity through detailed scales is important for both diagnostic and treatment recommendations. The Everyday Cognition (ECog) scale is a relatively new informant-rated measure of cognitive and functional abilities. In the present study, the discriminant validity of the ECog scale was evaluated in cognitively intact controls (CN) and in patients with mild cognitive impairment (MCI) and mild Alzheimer's disease (AD) from the Argentina-ADNI cohort to establish diagnostic accuracy. In addition, we compared the sensitivity and specificity of ECog against Functional Assessment Questionnaire (FAQ) scale to discriminate among the three groups. METHODS: We evaluated 15 CN, 28 MCI, and 13 mild AD subjects. External, convergent and divergent validity and internal consistency were examined. RESULTS: The average total score on the ECog was significantly different across the three diagnostic syndromes (p < .05). The ECog was more sensitive than FAQ in discriminating between CN and MCI patients and between MCI and AD subjects. The ECog showed a strong correlation with FAQ, and moderate correlations with neuropsychological tests. Cronbach's alpha was .98. CONCLUSIONS: The ECog scale is an efficient instrument for the differentiation of individuals with mild dementia or MCI from normal older adults, with good accuracy and good correlation with other tests measuring daily and cognitive functions. Comparing against FAQ, ECog was more useful in assessing changes in functionality in MCI patients.